Rotary speed responsive switch



Aug. 28, 1956 L. E. THATCHER 2,

ROTARY SPEED RESPONSIVE SWITCH Filed March 17, 1954 II Illllllll Illll Ill WNNIMMNNNRNNN H United States Patent ROTARY srnnn RESPONSIVE SWITCH Lewis E. Thatcher, Chicago, IlL, assignor to Gaylord Products, Incorporated, Chicago, Ill., a corporation of Delaware Application March 17, 1954, Serial No. 416,79

3 (Ilaims. (Cl. 200-80) This invention relates to improvements in a mechanism for making or breaking an electric circuit in relation to the speed of a rotating body and is a continuation-in-part of my copending application for patent Serial No. 308,085, filed September 5, 1952, now Patent No. 2,678,977, patented May 18, 1954.

in my copending application for patent herebefore identified, a device is illustrated and described for breaking an electric circuit in response to the rotary speed of a rotating body. The device comprises essentially a closed container in which a non-conducting liquid is adapted to be carried. A conducting plate is positioned at the bottom of the container beneath the liquid. Means is contemplated for rotating a pivotally or hingedly mounted vane within the container, the vane and plate being connected to an electrical circuit. As the vane is rotated, the frictional resistance of the liquid acting upon the vane causes the vane to cant and thus the lower edge of the vane, which is normally in contact with the plate, breaks contact with the plate and, thus, breaks the electrical circuit.

The present invention relates to a device for breaking an electrical circuit in response to the rotary speed of a rotating body and operates under the same general principle as that contemplated in my aforesaid application for patent except that the rotating vane is acted upon by air or other gaseous fluid whereby when said vane rotates at a predetermined speed the frictional resistance of the air or other gaseous fluid causes said vane to cant thereby breaking an external electrical circuit.

As an additional feature of the present invention the vane employed is constructed of relatively light weight material and has a face of relatively large area whereby movement of the vane encounters a large quantity of air or gas and can readily swing about its hinge.

As a further feature of the invention the contact between the vane and plate is relatively restricted so that frictional resistance at said contact zone is reduced to a minimum.

Other objects and advantages of the present invention will be apparent from the accompanying drawing and following detailed description.

In the drawing,

Fig. 1 is a sectional view of a device embodying the concepts of my present invention.

Fig. 2 is a transverse sectional view taken on line 22 of Fig. 1.

Fig. 3 is a fragmentary detailed perspective view of the rotating vane employed in my invention.

Although the present invention may be employed in substantially any environment and be responsive to the rotary speed of substantially any rotating body, for purposes of illustration, the invention will be described in its use upon an automobile to control a desired electrical circuit in response to the movement of the automobile. Hence, the speed responsive switch will be shown and described in association with the speedometer cable of the automobile.

Patented Aug. 28, 1956 Referring in detail to the drawing, 1 indicates generally the speed-responsive switch embodying the concepts of the present invention. The device 1 comprises a cupshaped body 2 having a top closure 3. The cup-shaped body 2 has. a bottom 4 and cylindrical side wall 5. Within the body 1, a central cylindrical boss 6 is positioned whereby an annular space 7 is provided in the body.

The body also carries a downwardly extending cylindrical sleeve 8 which is provided with an opening 9 for the reception of an end of 'a speedometer sheath 10 within which a speedometer cable 11 is carried. The cable 11 extends upwardly through the. boss 6 and also through a sleeve 12 comprising a portion of closure 3. The sleeve 12 is provided with an opening 13 adapted for the engagement of a spaced end 14 of the speedometer cable sheath.

Within the boss 6, a frictional gripping member 15 engages the speedometer cable 11, said member being embraced by a sleeve 16 which is rotatably positioned within boss 6. A cap 17 is rigidly positioned upon the sleeve 16 and member 15 and is journaled Within the closure 3 for rotation with the speedometer cable.

A rod 18 extends radially outwardly from cap 17 and is adapted to function as a hinge pin or 'hinge support for a vane 19, said vane carrying a sleeve 20 at its upper edge which loosely embraces the rod 18. The inner diameter of the sleeve 20 is greater than the diameter of rod 18 whereby said sleeve is permitted a degree of radial movement upon the rod. A lug 21 is carried at the outer end of rod 18- whereby axial movement of the sleeve 20 upon the rod is limited.

Vane 19 is constructed of relatively light gauge metal, preferably aluminum or the like and said vane has a relatively large face area. Secured to the lower edge of the vane 19', as by brazing, soldering or the like, is a relatively thin resilient copper contact plate 22. A metallic ring 23, preferably constructed of copper is positioned upon the bottom 4, the upper face of the ring being exposed to the zone '7.

The arrangement is such that when the vane 19 is stationary, the plate 22 makes electrical contact with ring 23. Within zone 7 air or other gaseous fluid is carried. Hence, when the speedometer cable 11 is rotated, thereby rotating vane 19, the vane encounters resistance from said air or gas and at a predetermined rotary speed the vane will be canted about the rod 18 whereby the lower edge of the plate 22 breaks contact with the ring 23.

Electrically, the speedometer cable, cap 17, vane 19 and plate 22 are grounded, as indicated at 24 in Fig. 1 and ring 23 connects with a conductor 24 which extends through the bottom 4. Both ground 24 and conductor 25 may comprise a portion of an external electrical circuit (not shown) whereby separation of plate 22 from ring 23 functions to break said electrical circuit.

Of course, it is not necessary that the zone 7 be a completely closed zone if air is the gaseous fluid employed, and as a matter of fact, in some instances it may be desirable to have the container 5 open at its top, or at least, have the zone 7 vented. It may be desired to maintain a super atmospheric pressure in zone 7, in which case, of course, the zone 7 will be sealed. A gas or vapor may be introduced into the zone 7 from any suitable source (not shown) through pipe 26, controlled by valve 27.

The speed at which the switch 1 responds will depend upon many factors which may be controlled to suit a predetermined purpose. For instance, the speed of vane 19 at which plate 22 breaks contact with ring 23 will depend upon the Weight of vane 19, the face area of said vane or the density of the gas or vapor within zone 7, all of which factors may be controlled within the broad concepts of the present invention.

If desired, the contact 22 may be eliminated, in which case the vane 19 will be so dimensioned that the lower edge or a portion thereof contacts the ring 23.

I claim as my invention:

1. An electric switch responsive to the rotary speed of a body which comprises, a frame, an electrically conductive relatively fiat ring mounted in substantially horizontal position on said frame with a gaseous atmosphere above said ring, an electrically conductive vane of greater width and length than thickness, means for hingedly suspending said vane above said ring with its lower edge portion adjacent said ring, a contact element carried by the lower edge portion of said vane for making electrical contact with said ring when said vane is stationary, means journaled in said frame for rotating said vane in a direction at substantially right-angles to the face of the vane and in a plane substantially parallel to said conductive ring through said gaseous atmosphere whereby the frictional resistance of said gaseous atmosphere upon said rotating vane cants said vane about its hinged suspension to cause the contact element to move away from and break contact with said ring, and means for connecting the conductive ring and vane and contact element in an electric circuit.

2. An electric switch responsive to the rotary speed of a body which comprises, a container carrying a gaseous atmosphere, an electrically annular fiat conductive member mounted in substantially horizontal position in said container, an electrically conductive vane of greater Width and length than thickness, means for hingedly suspending said element above said member with its lower portion in electrical contact with said member when said vane is stationary, means journaled in said container for rotating said vane in a direction at substantially right-angles to the face of the vane and in a plane substantially parallel to said conductive member through said gaseous atmosphere whereby the frictional resistance of said gaseous atmosphere upon the face of said rotating vane cants said vane about its hinged suspension to cause the lower portion thereof to move away from and break contact with said member, and means for connecting the conductive member and conductive vane in an electric circuit.

3. An electric switch responsive to the rotary speed of a body which comprises, a frame, an electrically annular flat conductive member mounted in substantially horizontal position on said frame with a gaseous atmosphere above said member, an aluminum vane of greater width and length than thickness, means for hingedly suspending said vane above said member with its lower portion in electrical contact with said member when said vane is stationary, means journaled in said frame for rotating said vane in a direction at substantially right-angles to the face of the vane and in a plane substantially parallel to said conductive member through said gaseous atmosphere whereby the frictional resistance of said gaseous atmosphere upon the face of said rotating vane cants said vane about its hinged suspension to cause the lower portion thereof to move away from and break contact with said member. and means for connecting the conductive member and vane in an electric circuit.

References Cited in the file of this patent UNITED STATES PATENTS 2,319,107 Brandt May 11, 1943 

